Generation of new knowledge on disease risk in cod farming

Atlantic cod (Gadus morhua L.) is an economically important aquaculture fish species around the North Atlantic. Currently the cod industry is experiencing increase in stocks, due to the production of high quality, fifth generation-domesticated cod juveniles. In 2021, there were approximately eight active cod farms in Norway, with total cod production of 6500 tons. This number is expected to increase to 25,000 tons in 2025, as new cod farming licenses for sea-based farms are being issued. Given that, these new cod farms will have to coexist with other sea-based fish farms, wild Atlantic cod and other marine fish species, it is important to generate new knowledge on the risk of disease spread.

The collective term “fish diseases” constitutes the most important cause of mortality in marine farmed salmon. Cod farms are mostly raised in open sea net pens. The practice of rearing high-density populations in open sea net-pens means fish are under constant threat of being infected and suffer from different infectious diseases. Diseases may cause great losses to farmed and wild fish, and control and eradication measures may cause significant costs. Moreover, disease has great impact on fish welfare. Thus, performing proper risk analysis that helps identify risk factors that are involved in occurrence of diseases and disease spread is paramount in limiting transmission, spread of diseases, and can contribute to sustainable cod aquaculture.

In this project, we will present an overview of the current knowledge on which pathogens are associated with disease in cod. We will document the current knowledge of the prevalence of the pathogens in land and sea-based cod farms, generate new knowledge on shedding and transmissibility of pathogen to new host, all of which may lead to the disease and finally, we will develop a knowledge-based risk analysis method to assess disease spread.